Traditionally, fabric conditioning has been carried out either during the rinsing step of a fabric washing and rinsing process or during tumble drying of the fabric. Typically, rinse conditioning is accomplished by adding a liquid dispersion of a rinse conditioning agent to the rinse liquor. The liquid dispersion was traditionally distributed and made available to consumers as a ready to use aqueous dispersion. More recently, concern for the environment and consumer convenience has led to the sale of concentrated aqueous dispersions which are either used in smaller amounts or are mixed with water to form a dilute composition before use.
In EP 234082 it has been proposed to supply rinse conditioner as a solid block. This approach requires the use of a special restraint for the block and may also require the modification of the washing machine enable the block to be dissolved and dispensed by a spray system.
Various proposals have been made to supply fabric softener in granular or powdered form.
EP 111074 discloses a powdered rinse conditioner based on a silica carrier for the softening agent. A disadvantage of using a carrier such as silica is that it can cause bulking of the product and appears to serve no function beyond making the powder compatible with other ingredients that may be contained in a washing powder.
WO 92/18593 describes a granular fabric softening composition comprising a nonionic fabric softener and a single long alkyl chain cationic material. The specification teaches that effective cationic softening compositions when used in granular form exhibit poor dispersion properties and so, despite the obvious environmental and transport saving advantages of selling a water free powdered rinse conditioner, manufacturers have not done so.
EP-B1-0568297 discloses a powdered rinse conditioner comprising a water insoluble cationic active and a nonionic dispersing agent.
It is known that solid fabric conditioners can be formed by combining quaternary ammonium compounds with a water soluble carrier such as urea. The problem is that these products often do not have good flow properties and/or do not disperse well in liquids.
U.S. Pat. No. 5,259,964 (Colgate-Palmolive) discloses a free flowing spray-dried rinse conditioner. U.S. Pat. No. 4,427,558 (Unilever) discloses a method of preparing fabric softening particles comprising a cationic fabric conditioning material, urea and a salt of a fatty acid.
It is also known to provide zeolite as a builder for a detergent powder compositions. Quaternary ammonium materials are disclosed in such compositions typically for giving softness in the wash benefits.
JP 63008493 discloses detergent compositions comprising from 0.5 to 10 wt % of a cationic quaternary ammonium materials in combination with zeolite.
JP 60088098 discloses granular detergent compositions containing urea and anionic surfactant. A zeolite may be present.
Rinse conditioners which comprise a quaternary ammonium material in combination with a zeolite are disclosed in GB 2124644, JP 59008800, JP 59024800 and U.S. Pat. No. 4,510,073 (all Lion).
EP-A1-269982 discloses a post-wash conditioner composition comprising, by weight, (a) 5-80% of at least one natural and/or synthetic layer silicate, (b) 1-20% of at least one known neutralisation agent and acidification agent such as citric acid, malic acid, oxalic acid, lactic acid or toluene-sulphonic acid (c) 1-20% of at least one known disintegration agent such as citric acid bicarbonate (d) 1-30% of at least one extender or carrier substance such as (NH4)2SO4, zeolite A or urea, (e) 0-50% of at least one binder and (f) 0-10% of a fatty acid ester.
There is no disclosure of zeolite being used in solid fabric conditioning compositions to improve dispersion of a quaternary ammonium fabric softening material and/or to provide good flow properties of the solid even across a wide range of levels of the softening active in the composition.
GB-A-2366801 relates to solid detergent compositions comprising clay fabric softeners. The cationic surfactants disclosed are single long chain quaternary ammonium materials typically used for detergency boosting.
GB-A-2141730 and GB-A-2140820 both disclose a particulate perfume-containing carrier for laundry compositions containing at least 75% of a clay mineral or a zeolite.
GB-A-2124644 discloses a method for granulating cationic surfactants. Example 1 describes a composition comprising 100 parts of a quaternary ammonium salt, 20 parts of silica, 45 parts of aqueous Liponox NCH solution and 70 parts of zeolite. There is no mention of a carrier material.
GB-A-1591515 and U.S. Pat. No. 4,339,335 both refer to free-flowing, high bulk density, particulate, detergent fabric softener compositions comprising from 4 to 12% of a non-ester linked cationic softening agent.
Surprisingly, we have now found that the incorporation of a zeolite into a solid fabric conditioning composition based on a cationic fabric softener and a carrier, such as urea, provides excellent powder properties, for example the ability to flow freely, and better dispersion of the cationic softener in water.
Further advantages are that the solid, and particularly powder, compositions of the present invention have an attractive appearance both as a solid and when dispersed in liquid.